The present invention relates to a damper provided between a suspended device and an outer casing thereof for preventing the suspended device from receiving unexpected shock.
An audio device such as a home CD player is designed so as to be horizontally disposed. However, a car CD player is disposed horizontally or vertically depending on the space for arranging the player.
The inventors of the present invention have proposed a CD player where a pickup normally operates either in the vertical disposition or the lateral disposition of the player. For example, Japanese Patent Application 1-109666 discloses such a CD player which is shown in FIG. 9.
Referring to FIG. 9, a car CD player 1 comprises an outer casing 2 and an inner casing 3 mounted in the casing 2. The inner casing 3 is supported in the casing 2 through a pair of springs 11 provided between each of the longitudinal inner sides 2a of the casing 2 and opposing outer sides 3a of the inner casing 3. Dampers 4 are provided between the outer casing 2 and the inner casing 3 at the four corners. Each damper 4 is charged with viscous oil such as a silicon oil. A supporting rod 4a provided at one end of the damper 4 is connected to a support plate 3b formed at each corner of the inner casing 3. The other end of the damper 4 is connected to the outer casing 2.
In one lateral side of the inner casing 3 is formed with an opening 5 through which a magazine M is inserted therein. The magazine M has a plurality of vertically layered trays t each of which holds a compact disk D. When the magazine M is inserted in the inner casing 3 through the opening 5, a selected tray t is moved to a playback position shown in the figure through a loading mechanism. The disk D is thereafter rotated at a predetermined speed so that information written on the disk D is read out by a pickup 30.
The CD player 1 is horizontally disposed as shown in FIG. 9, or vertically disposed in an upright position by rotating the player about a lateral axis 90 degrees and mounted in a trunk of a motor vehicle. The CD player 1 is operated through an operation panel provided in the interior of the vehicle to play the required disks D.
The lower end of each spring 11 is rotabably mounted on a support pin 10 secured on the side 3a. The upper end of the spring is rotatably mounted on a lobe 12a of a rotational disk 12 which is parallel with the side 2a and rotatably mounted on the side 2a of the inner wall of the outer casing 2 through a pin 13 at the center thereof. Each disk 12 has a pair of arcuated slits 14 and 15 formed symmetrically with respect to the pin 13. Each slit 14, 15 extends across an angle of 90 degrees Guide pins 16 and 17 secured to the sides 2a engage with the slits 14 and 15, respectively The springs 11 in cooperation with the dampers 4 absorb the shocks and vibrations of the vehicle when it is driven.
When mounting the CD player 1 in the upright position, the four rotational disks 12 on the sides 2a are rotated 90 degrees in the counterclockwise direction. Thus, the springs 11 extend in the vertical direction, thereby vertically suspending the inner casing 3.
As shown in FIG. 10, the conventional damper 4 provided between the outer and inner casings 2 and 3 comprises a flexible damper body a made of soft rubber, a cylindrical holder c made of hard rubber wherein the body a is inserted, viscous oil b trapped inside the body a, and a support rod e engaged in a recess d at an end thereof. The other end of the rod e is connected to the inner casing 3. When the rod e vibrates, the oil b is agitated, thereby absorbing the vibration.
However, when a large outer force caused by a shock or vibration is exerted on the damper rod e, the rod e deflects downwardly as shown in FIG. 11. As a result, a gap f is formed between the holder c and the upper periphery of the body a, and the recess d moves toward the lower periphery of the body. Hence the quantity of oil between the lower periphery of the body a and the recess d decreases so that the agitation of the viscous oil is restricted. Consequently, shocks and vibrations cannot be sufficiently absorbed, causing harm to the suspended device, or in the case of a reproducing device, causing noises.